Rama is a smartphone app that not only guides you through your favorite cities while giving you historical details, it also makes the past come alive through archival photographs that show users exactly what a particular destination or site once looked like. See the rocky swamp that is now Central Park, walk through Chicago right after the Great Fire, experience the wild atmosphere of Mardi Gras during the Depression, or visit the few lonely buildings in San Francisco after the Earth quake hit in 1906.